AB0592 IS IT TIME TO DISSECTING GIANT CELL ARTERITIS INTO SUBPHENOTYPES? A CLOSE LOOK TO DATA OF EASTERN MEDITERRANEAN VASCULITIS CENTRE
Authors: G. Sandal Uzun, Ö. Gököz, Y. Tahillioğlu, S. Lotfi Sadigh, A. A. Tan, S. Ardali, B. Armagan, L. Kiliç, İ. S. Idilman, M. R. Onur, S. Kadayifçilar, T. Hazirolan, O. Karadag
Journal: Annals of the Rheumatic Diseases (2022)

Background Patients with giant cell arteritis (GCA) have heterogeneity in terms of not only symptoms and findings but also extent of arterial involvement. In era of personalized medicine, therapy of patients is based on these diverse parameters. Objectives This study is aimed to identify subphenotypes of GCA, treatments have been used and outcomes in a prospective database of Eastern Mediterranean Vasculitis Centre. Methods Among 2454 patients recorded into Hacettepe University Vasculitis Research Centre database since October 2014; 181 of them were Takayasu’s arteritis and 89 of them GCA. 17 GCA patients were excluded due to missing data. Patients were grouped as Cranial GCA, Cranial GCA+ PMR, Cranial and LV GCA + PMR, Cranial and LV GCA, and LV GCA. Demographic and clinical findings, histopathological and imaging data as well as outcome was collated for each subphenotype. Results Of 72 patients enrolled into further analysis, a female predominance (72.2%) was observed with mean age at diagnosis of 68.3(±8.2) years. Seventy-four percent of patients had cranial GCA (Figure 1) and leading subphenotype of all patients was only cranial GCA. Usage of temporal artery biopsy (TAB), temporal artery and axillary artery ultrasonography, and imaging modalities were different according to phenotypes of GCA. Figure 1. Distribution of GCA subphenotypes Of the 38 patients having TAB, 20(42.9%) were consisted with GCA. The main histopathological finding were inflammation rich in lymphohistiocytic cells in the temporal artery (44.7%) and fragmentation and loss of integrity of the internal elastic lamina (36.8%). All of the patients have been used corticosteroids with a median starting dose of 16 mg/day(8-64) had used pulse therapy. Any of conventional DMARDS (AZA, MTX, LEF, CYC) have been used in 60 of patients. In all cases, Tocilizumab was recommended after resistant/intolerant to conventional DMARDs (n=6). Follow-up data was based on 64 patients. During a median 5,8 (±4.0) years follow-up, 6 (9.3%) patients deceased. Thirteen (20.3%) had one and more relapses, 8(61.5%) from isolated GCA group and 4(30.7%) from Only LV GCA group. Conclusion GCA is less frequent than TAK in our centre. Female predominance and a seventh decade of disease onset was observed in our cohort. Heterogeneity of disease was observed in or cohort along with different frequently used diagnostic confirmatory modality among subphenotypes. Relapse rate was 20 percent during a 6-year follow up with a 83% additional DMARD usage. References [1]K. Bates Gribbons 1 , Peter C Grayson 1 , et al Diagnostic Assessment Strategies and Disease Subsets in Giant Cell Arteritis: Data From an International Observational Cohort, Arthritis Rheumatology, 2020 Apr;72 Table 1. Confirmatory modality of GCA diagnosis and treatments of subphenotypes Only cranial GCA(n=38) Cranial GCA+PMR(n=6) Cranial GCA+LV GCA+ PMR(n=2) Cranial+LV GCA(n=5) LV GCA+PMR (n=7) Only LV GCA (n=14) Diagnosed confirmed by TAB(Total n=26) 20 4 2 Temporal ultrasonography(Total n=24) 18 2 1 2 1 PET CT/Vasculitis MR/VasculitisBT (Total n=22) 1 3 6 12 Only steroidn=12 6 2 1 3 Pulse steroidn=14 8 1 1 4 Methotrexaten=35 17 2 2 1 6 7 Leflunomiden=3 2 1 Azatioprinen=19 12 2 1 1 3 Cyclophosphamiden=1 1 Tosilizumabn=8 6 2 Disclosure of Interests None declared